Conventional golf balls can be divided into two general classes: solid and wound. Solid golf balls include one-piece, two-piece (i.e., solid core and a cover), and multi-layer (i.e., solid core of one or more layers and/or a cover of one or more layers) golf balls. Wound golf balls typically include a solid, hollow, or fluid-filled center, surrounded by a tensioned elastomeric material, and a cover. Solid balls have traditionally been considered longer and more durable than wound balls, but also lack the preferred “feel” provided by the wound construction.
By altering ball construction and composition, manufacturers can vary a wide range of playing characteristics, such as compression, velocity, “feel,” and spin, each of which can be optimized for various playing abilities. In particular, a variety of core and cover layer(s) constructions, such as multi-layer balls having dual cover layers and/or dual core layers, have been investigated. These golf ball layers are typically constructed with a number of polymeric compositions and blends, including polybutadiene rubber, polyurethanes, polyamides, and ethylene-based ionomers.
One problem sometimes encountered by manufacturers when attempting to construct multi-layered golf balls, however, is improper adhesion between layers. This problem arises when the compositions of adjacent layers are chemically incompatible, even if only by a small amount, or when processing conditions required for a particular layer are inconsistent with those required for an adjacent layer. Therefore, a need exists for development of a better adhesive promoter between layers.